Additive manufacturing (AM), also known as direct digital manufacturing, refers to a wide range of processes for the direct fabrication of final parts and/or functional prototypes using rapid prototyping technology. In AM, parts are fabricated by deposition using a heat source to locally melt material, forming a melt pool. As the heat source is translated across the part being fabricated, a bead formed of the moving melt pool with solidified material behind it is formed. Material is fed into the melt pool (either directly or via a powder applied to the surface of the part) and the part is built up one melt pool bead at a time. AM is used for Free Form Fabrication (F3), which is used for the rapid manufacture of a complete part; and for additive manufacturing and repair (AMR), which adds one or more features to an existing component, either as a manufacturing step or for component repair. For instance, AM can be used to build parts from titanium alloys, which has potential applications in the aerospace and medical implant industries.